EventFilter consume() does not prevent SpaceChars in TextField - javafx-8

Question

I have a JavaFX GUI where I wish to intercept the pressing of the SpaceBar and use it to call a method. I wrote an EventFilter that seems to do the trick. It includes the command event.consume() which I believe is supposed to keep the KeyEvent from propagating to the various controls.
My issue is that when I added a TextField, and this field has the focus, the Spacebar presses are not being consumed as I thought they would. The " " are captured by the TextField. I would like to intercept and prevent the " " from being added to the TextField.
What am I leaving out in the code below in order to keep " " from reaching the TextField? The api, if I am reading it correctly, says that filters registered with a parent control can intercept an event before it reaches the children nodes. But even when putting the filter directly on the TextField, I am still having " " chars appear in the TextField.
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.input.KeyCode;
import javafx.scene.input.KeyEvent;
import javafx.stage.Stage;
public class SpaceIntercept extends Application implements EventHandler <KeyEvent>
{
public static void main(String[] args)
{
Application.launch(args);
}
#Override
public void start(Stage primaryStage)
{
TextField textField = new TextField("asdf");
Group root = new Group();
Scene scene = new Scene(root, 200, 100);
scene.addEventFilter(KeyEvent.ANY, event -> handle(event));
// root.addEventFilter(KeyEvent.ANY, event -> handle(event));
// textField.addEventFilter(KeyEvent.ANY, event -> handle(event));
root.getChildren().add(textField);
primaryStage.setScene(scene);
primaryStage.show();
}
#Override
public void handle(KeyEvent event)
{
if (event.getCode() == KeyCode.SPACE)
{
if (event.getEventType() == KeyEvent.KEY_PRESSED)
{
System.out.println("Code that responds to SpaceBar");
}
event.consume();
}
}
}

Answer 1

The text field is probably listening for KEY_TYPED events. As is well-documented, getCode() returns KeyCode.UNDEFINED for a KEY_TYPED event. Thus you do not catch this case.
You can check for the character variable as well as the code variable to handle all cases:
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.input.KeyCode;
import javafx.scene.input.KeyEvent;
import javafx.stage.Stage;
public class SpaceIntercept extends Application implements EventHandler <KeyEvent>
{
public static void main(String[] args)
{
Application.launch(args);
}
#Override
public void start(Stage primaryStage)
{
TextField textField = new TextField("asdf");
Group root = new Group();
Scene scene = new Scene(root, 200, 100);
scene.addEventFilter(KeyEvent.ANY, event -> handle(event));
// root.addEventFilter(KeyEvent.ANY, event -> handle(event));
// textField.addEventFilter(KeyEvent.ANY, event -> handle(event));
root.getChildren().add(textField);
primaryStage.setScene(scene);
primaryStage.show();
}
#Override
public void handle(KeyEvent event)
{
if (event.getCode() == KeyCode.SPACE || " ".equals(event.getCharacter()))
{
if (event.getEventType() == KeyEvent.KEY_PRESSED)
{
System.out.println("Code that responds to SpaceBar");
}
event.consume();
}
}
}

Answer 2

A simple solution i can think,which although doesn't blocks the space from being added to the TextField,but it replaces it after it has been added almost instantly is adding a changeListener to the TextProperty of the TextField:
textField.textProperty().addListener((observable,oldValue,newValue)->{
textField.setText(textField.getText().replace(" ", ""));
});
This may also be helpfull http://fxexperience.com/2012/02/restricting-input-on-a-textfield/